Known fill level measuring devices comprise a parabolic aerial that transmits or receives microwaves so as to determine the fill level of a medium in a feed material container. In this setup the parabolic aerial of such a fill level measuring device is, for example, arranged within a container.
Hitherto known parabolic aerials and measuring devices that operate with radar waves or microwaves to determine the fill level of a medium in a container may be associated with undesired reflections, which among other things may be caused by the input coupling system and the aerial mirror itself. At short range, such undesired reflections result in at times considerable and undesirable reduction in the signal-to-noise ratio, which may result in the echo at short range disappearing in the noise. In particular in the measuring range below one meter this interfering noise is significant.